Method for detecting pressure resistance of pressure vessel

Abstract

The invention relates to a method for detecting the pressure resistance of a pressure vessel. The method comprises the following steps: step 1, preparing a reagent; step 2, preparing equipment; 3, the pressure container is hoisted; step 4, pipeline connection; 5, injecting a reagent; step 6, performance detection; step 7, ending the test; special detection equipment adopted by the detection method is provided with a transparent detection cylinder, and during detection, methyl orange and an alkaline solution are utilized to develop yellow color, phenolphthalein and the alkaline solution are utilized to develop red color, so that detection personnel can timely judge whether the pressure container has cracks and deforms, and accurately record corresponding pressure; according to the color change position, the positions of cracks and deformation of the pressure vessel are judged and identified, and the two different color changes enable detection personnel to accurately distinguish two conditions of crack occurrence and deformation occurrence, so that the detection personnel can conveniently take corresponding measures in time and stop a test in time, and the detection efficiency and the detection safety are improved.

Description

Technical Field

[0001] The invention relates to the technical field of pressure vessels, and in particular to a method for detecting the pressure resistance performance of a pressure vessel. Background Art

[0002] The pressure resistance performance test of pressure vessels is a necessary technology for the manufacturing of high-end pressure vessel equipment. The pressure resistance performance test of pressure vessels is used to detect whether the pressure bearing capacity of pressure vessels meets the technical requirements in order to eliminate the safety hazards of pressure vessels. Pressure vessels are usually composed of an annular cylinder, an upwardly arched upper end and a downwardly arched lower end. Due to their own arched structure, the pressure bearing strength of the upper and lower ends is usually greater than that of the annular cylinder. The pressure bearing capacity of the annular cylinder determines the upper pressure limit of the pressure vessel. Therefore, the pressure bearing capacity of the annular cylinder of the pressure vessel is the focus of the pressure resistance performance test of the pressure vessel.

[0003] The Chinese invention patent with publication number CN116008086B provides a mobile pressure vessel pressure test stand and a test method thereof. When the pressure vessel is subjected to a pressure test, the test stand detects the deformation of the circumferential side wall of the pressure vessel through a circumferential detection mechanism. When the deformation of the circumferential side wall of the pressure vessel changes, the tension value of the surrounding pull rope changes with the deformation of the circumferential side wall of the pressure vessel, and the deformation of the circumferential side wall of the pressure vessel is detected by the change of the tension value of the surrounding pull rope. The test stand is only applicable to the case where there are no cracks in the pressure vessel. If there are cracks in the pressure vessel itself or cracks appear during the detection process, the pressure leaks. Only the deformation of the circumferential side wall of the pressure vessel cannot timely warn the inspector. When the initial crack is relatively fine, the pressure value caused by the slight leakage drops slightly. Compared with the pressure increase during the pressurization process, it is difficult for the inspector to find the leakage problem in time by observing the pressure reading. As the pressure increases, the crack suddenly increases, causing the high-pressure fluid to suddenly spray out, posing a threat to the on-site facilities and the life safety of personnel. There are great safety hazards in the detection process.

[0004] The Chinese utility model patent with publication number CN211626832U provides a pressure vessel anti-leakage defect detection device based on the action of gas and liquid. The device performs leakage detection on the pressure vessel. When there are small cracks on the pressure vessel to be detected and a small amount of leakage occurs, under the pressure of high-pressure ammonia, the leaked ammonia is injected into the detection box from the negative pressure pipe, reacts with phenolphthalein, and gives an obvious judgment indication, thereby effectively discovering and monitoring the tiny gaps in the pressure vessel. However, the detection device can only detect whether there are small cracks on the pressure vessel, but cannot clearly point out the specific location of the cracks on the pressure vessel. When cracks are detected in the pressure vessel, other means, such as magnetic particle detection, are needed to detect the entire surface of the pressure vessel, so as to find the location of the cracks and then perform subsequent repair work. The whole process is complicated and cumbersome, and the detection efficiency is low.

[0005] Therefore, the present invention proposes a method for testing the pressure resistance performance of a pressure vessel to solve the above-mentioned problem. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for detecting the pressure resistance performance of a pressure vessel. On the one hand, it can promptly detect whether there are or have cracks in the pressure vessel and indicate the location of the cracks. On the other hand, it can promptly detect whether the pressure vessel is deformed and identify the deformation location, thereby improving the detection efficiency and detection safety.

[0007] In order to solve the above technical problems, the technical solution of the present invention is: a method for testing the pressure resistance performance of a pressure vessel, the innovation of which is: comprising the following steps: Step 1, reagent preparation: prepare methyl orange solution, phenolphthalein solution and alkaline solution in three reagent tanks respectively, sample the solutions after the preparation is completed, mix the methyl orange solution sample with the alkaline solution sample, and the phenolphthalein solution sample with the alkaline solution sample respectively, and observe whether the color changes; Step 2, equipment preparation: operate the special testing equipment, make the transparent testing cylinder and the pressure vessel clamp of the special testing equipment in the open state, check whether the ejector pins on the special testing equipment are normal, and ensure that all ejector pins are in the closed state; Step 3, hoisting the pressure vessel: use the lifting equipment to hoist the pressure vessel into the transparent detection tube of the special detection equipment for positioning support, operate the special detection equipment to close the transparent detection tube of the special detection equipment and the pressure vessel clamp, and unhook the lifting equipment; Step 4, pipeline connection: connect the pipeline between the methyl orange solution reagent tank and the pressure vessel, and the pipelines between the other two reagent tanks and the special testing equipment, and perform a sealing test on each pipeline; Step 5, reagent injection: a crack color development cavity is formed between the pressure vessel and the transparent detection tube of the special detection equipment, and the detection tube of the special detection equipment has a phenolphthalein containing cavity and a deformation color development cavity. Methyl orange solution and phenolphthalein solution are respectively injected into the pressure vessel and the phenolphthalein containing cavity, and alkaline solution is injected into the crack color development cavity and the deformation color development cavity. After the injection is completed, the liquid level change in the crack color development cavity is observed to ensure that the crack color development cavity does not leak; Step 6, performance test: pressurize the pressure vessel to a safe pressure and maintain the pressure for 30 minutes, observe whether there is any color change in the crack color-developing cavity, if there is any color change, record the location of the color change and stop the test, if there is no color change, intermittently pressurize the pressure vessel at a uniform speed according to the test requirements, maintain the pressure for 30 minutes after each pressure increase to the required pressure value of a stage, until the pressure is increased to the maximum pressure value required by the test, after maintaining the pressure for 30 minutes, reduce the pressure to 80% of the maximum pressure value required by the test, and maintain the pressure for 1-2 hours. During the experiment, continuously observe the color change in the deformation color-developing cavity and the crack color-developing cavity, once the color change occurs in the deformation color-developing cavity or the crack color-developing cavity, record the location of the color change and the pressure value, stop the test and release the pressure; Step 7, end of the test: After stopping the test, release the pressure in the pressure vessel, vent the solutions in the pressure vessel, crack color development chamber, phenolphthalein containing chamber and deformation color development chamber, operate the special detection equipment, open the transparent detection tube and pressure vessel clamp of the special detection equipment, and use the lifting equipment to lift the pressure vessel away from the special detection equipment.

[0008] Furthermore, the alkaline solution is a sodium bicarbonate solution.

[0009] Furthermore, in step 1, fluorescein isothiocyanate is added to the methyl orange solution. In step 7, if the test is stopped due to color change in the crack color development chamber, after opening the transparent detection tube and the pressure vessel clamp of the special detection equipment, a purple light is used to illuminate the surface of the pressure vessel corresponding to the position where the color change occurs, and the crack position is marked on the wall of the pressure vessel according to the fluorescent indication position of the fluorescein.

[0010] Furthermore, in step 3, when hoisting the pressure vessel, an axial positioning line is drawn on the outer wall of the pressure vessel in advance, and an axial positioning reference line is drawn on the transparent detection tube of the special detection equipment. When the pressure vessel is hoisted normally into the transparent detection tube of the special detection equipment by using the lifting equipment, the pressure vessel is rotated so that the circumferential positioning line on the pressure vessel overlaps with the axial positioning reference line on the transparent detection tube.

[0011] Furthermore, in step 5, when injecting the alkaline solution into the crack color development cavity and the deformation color development cavity, the alkaline solution is first injected into the deformation color development cavity, and then the alkaline solution is injected into the crack color development cavity; The liquid level in the deformation color development chamber is lower than the liquid level in the phenolphthalein containing chamber.

[0012] Furthermore, in step 7, if the test is stopped due to color change in the deformation color developing chamber, after venting the solutions in the pressure vessel, the crack color developing chamber, the phenolphthalein containing chamber and the deformation color developing chamber, the position of the opened ejector pin is observed and recorded, and the position of the opened ejector pin is rechecked against the color change position of the deformation color developing chamber recorded in step 6.

[0013] Further, the special testing equipment includes a test bench, a transparent testing cylinder and a pressure vessel clamp; The test bench is arranged horizontally; The central axis of the transparent detection cylinder is vertically arranged above the test bench. The transparent detection cylinder includes a bottom support seat and a plurality of side cylinders. The plurality of side cylinders are movably arranged around the bottom support seat through a slider assembly and are driven to synchronously move close to or away from the bottom support seat by a gear drive assembly. Each side cylinder moves between a first position and a second position. When each side cylinder synchronously moves to the first position, the transparent detection cylinder is in an open state. When each side cylinder synchronously moves to the second position, the transparent detection cylinder is in a closed state. Two adjacent side cylinders and between the side cylinder and the bottom support seat are sealed. The side cylinder cooperates with the bottom support seat to form a pressure vessel placement cavity. The top of the pressure vessel placement cavity has a first opening for the pressure vessel to enter. A pressure vessel outlet pipe positioning groove is provided in the middle of the top surface of the bottom support seat, and a plurality of pressure vessel support blocks are evenly arranged around the pressure vessel outlet pipe positioning groove on the top surface of the bottom support seat, and the top surface of the pressure vessel support block has an arc-shaped surface matching the outer wall of the lower end of the pressure vessel; The side cylinder comprises a bottom plate, a side plate, an intermediate plate and a plurality of ejector pins. The side plate is arranged around the bottom plate and forms a solution groove above the bottom plate. The intermediate plate is arranged inside the side plate and separates the solution groove into a phenolphthalein containing chamber with a second opening on the top and a deformation color developing chamber. The phenolphthalein containing chamber is located inside the deformation color developing chamber. A plurality of sleeves corresponding to the ejector pins are arranged in the phenolphthalein containing chamber. Both ends of the sleeve are connected to the side plate and the intermediate plate. A plurality of through holes connecting the phenolphthalein containing chamber and the deformation color developing chamber are evenly arranged around the sleeve on the intermediate plate. A plurality of blocking blocks corresponding to the through holes are arranged at the end of the ejector pin. The ejector pin is movably inserted into the sleeve by a reset spring and is sealed and connected to the sleeve. The blocking blocks of the ejector pins are sealed and pressed in the through holes under the pulling force of the reset spring. One end of the ejector pin away from the blocking block extends into the pressure vessel placement chamber. The pressure vessel clamping jaws are provided with two and are symmetrically arranged on both sides above the transparent detection tube. The two pressure vessel clamping jaws are driven by a linear drive to move closer to or farther from each other.

[0014] Further, the ejector pin comprises a rod body, one end of the rod body extends outwardly in a radial direction to form a disc, a side of the disc close to the phenolphthalein accommodating chamber extends outwardly in an axial direction to form a blocking block, a second distance is left between the blocking block and the rod body, a side of the blocking block away from the rod body is an inclined surface, the inclined surface is inclined from the side close to the phenolphthalein accommodating chamber to the direction away from the central axis of the rod body, a disc accommodating groove for the disc to enter is provided on the side wall of the middle plate close to the deformation color development chamber, a through hole is provided on the bottom surface of the disc accommodating groove, and the shape of the through hole matches the blocking block; A spring limit block extends outwardly in the radial direction on the side wall of the rod body, and a limit block accommodating groove for accommodating the spring limit block and allowing the spring limit block to move with the ejector pin is opened on the inner wall of the sleeve. The spring limit block is arranged in the limit block accommodating groove, and the return spring is sleeved on the outside of the rod body. One end of the return spring is connected to the spring limit block, and the other end is connected to the side wall of the limit block accommodating groove.

[0015] Furthermore, in step 3, when the transparent detection tube of the dedicated detection device is closed, a first distance is left between the inner end of the ejector pin of the dedicated detection device and the outer side wall of the pressure vessel, and the first distance is the same as the maximum allowable deformation value of the pressure vessel.

[0016] Further, the slider assembly is arranged between the test bench and the transparent detection cylinder, each side cylinder of the transparent detection cylinder corresponds to two slider assemblies arranged in parallel, the slider assembly includes a slider, a guide rail and a screw, the guide rail is installed on the top surface of the test bench, the top of the slider is connected to the bottom surface of the corresponding side cylinder, the bottom of the slider is slidably installed on the guide rail, the screw is rotatably arranged above the guide rail through a mounting seat, a threaded hole matching the screw is opened on the slider, the screw is threadedly connected in the threaded hole, and a first gear is installed at the end of the screw; The gear drive assembly is arranged below the test bench, and the gear drive assembly includes a rotating motor and a commutator. The commutator is installed on the bottom surface of the test bench, and the commutator has a power input end and a plurality of power output ends corresponding to each side cylinder one by one. The rotating end of the rotating motor is connected to the power input end, and each power output end is equipped with a second gear. A through slot is opened on the test bench for each second gear to extend out. The second gear extends to the top of the test bench through the through slot and is meshed and connected with the first gears of the two slider assemblies of the corresponding side cylinder.

[0017] The advantages of the present invention are: The special detection equipment used in the detection method of the present invention has a transparent detection tube. During the detection, methyl orange and an alkaline solution are used to develop yellow color, and phenolphthalein and an alkaline solution are used to develop red color, so that the detection personnel can timely judge whether cracks and deformations occur in the pressure vessel, accurately record the corresponding pressure, and judge and identify the positions of cracks and deformations of the pressure vessel according to the positions of color changes. Moreover, the two different color changes enable the detection personnel to accurately distinguish between the two situations of cracks and deformations, so that it is convenient for the detection personnel to take corresponding measures in time and stop the test in time, thereby improving the detection efficiency and detection safety.

[0018] The alkaline solution in the present invention is a sodium bicarbonate solution, which has a relatively weak alkalinity and has a relatively low corrosiveness to the surface of the transparent detection tube and the pressure container, and is inexpensive, thereby reducing the detection cost.

[0019] The present invention adds fluorescein isothiocyanate to a methyl orange solution. After the test, the crack position can be more accurately located by irradiation with a purple lamp, thereby improving the detection accuracy. Furthermore, the fluorescein isothiocyanate has good solubility in both water and a sodium bicarbonate solution and has excellent fluorescence performance. The fluorescence of the fluorescein isothiocyanate is yellow, which has little effect on the yellow color development of methyl orange in an alkaline solution, and has excellent performance.

[0020] The present invention draws an axial positioning line on the outer side wall of the pressure vessel in advance, and draws an axial positioning reference line on the transparent detection tube of a special detection device, and adopts a positioning method in which the circumferential positioning line on the pressure vessel overlaps the axial positioning reference line on the transparent detection tube. When the position of cracks or deformation on the pressure vessel is judged according to the color change position later, this is used as a reference to improve the accuracy of position judgment.

[0021] According to the detection method of the present invention, when injecting alkaline solution into the crack color developing cavity and the deformation color developing cavity, the alkaline solution is first injected into the deformation color developing cavity, and pressure is applied to the ejector pin toward the crack limiting cavity. Then, the alkaline solution is injected into the crack color developing cavity, which can effectively avoid the situation that liquid agitation is formed when the alkaline solution is injected into the crack color developing cavity, causing the ejector pin to be accidentally opened; and the liquid level in the deformation color developing cavity is lower than the liquid level in the phenolphthalein containing cavity. When the ejector pin is pushed outward by the deformation of the pressure vessel, the phenolphthalein solution in the phenolphthalein containing cavity can smoothly enter the outer deformation color developing cavity, and color changes occur in the deformation color developing cavity, so that operators can judge the color change more timely and accurately, and at the same time reduce the contamination probability of the phenolphthalein solution, which is conducive to reuse.

[0022] The present invention can effectively improve the judgment accuracy of the deformation position of the pressure vessel and improve the detection accuracy by observing and recording the position of the opened ejector pin and re-checking the recorded color change position of the deformation color display cavity.

[0023] When the special detection equipment of the present invention is in use, after the pressure vessel is hoisted into the transparent detection cylinder, the liquid outlet pipe at the bottom of the lower end of the pressure vessel enters the positioning groove of the liquid outlet pipe of the pressure vessel, and the pressure vessel is positioned and supported by the pressure vessel support block. The top of the pressure vessel is supported and fixed by the pressure vessel clamp to fix the pressure vessel, and then the gear drive assembly is used to drive the cylinders on both sides to synchronously close the transparent detection cylinder, so that a crack color development cavity is formed between the inner wall of the transparent detection cylinder and the outer wall of the pressure vessel. The operation process is simple, and the entire detection cylinder is made of transparent material, which is convenient for detection personnel to observe the color changes in each color development cavity.

[0024] The ejector of the present invention is designed with a disk at the top of the rod, which can not only limit the axial lifting, but also increase the area of ​​the end face of the ejector close to the deformation color development cavity, thereby improving the force and avoiding accidental opening of the ejector; by designing the side of the blocking block away from the rod body as an inclined surface, the shape of the through hole matches the blocking block. With this structural design, as long as the ejector is pushed and moved by the pressure vessel when it is deformed, the through hole can be immediately opened, so that the phenolphthalein in the phenolphthalein accommodating cavity enters the deformation color development cavity and contacts with the alkaline solution for color development, thereby accelerating the color development speed and ensuring the timeliness of deformation detection; by arranging a reset spring, on the one hand, it is ensured that the ejector is opened by the thrust only when the pressure vessel is deformed during the test, thereby avoiding accidental opening; on the other hand, after the test, when the transparent detection tube is opened, the ejector automatically returns to the closed state for next use.

[0025] The present invention allows a first distance equal to the maximum allowable deformation value of the pressure vessel to be left between the inner end of the ejector pin of the special detection equipment and the outer wall of the pressure vessel. This method ensures that as long as the ejector pin moves and a color change occurs in the deformation color display cavity, it can be determined that a transitional deformation has occurred in the pressure vessel, thereby clearly reading the pressure value corresponding to the transitional deformation of the pressure vessel.

[0026] The present invention can effectively reduce the space occupied by the components and make the structure of the special detection equipment more compact by respectively installing the slider component and the gear drive component on the upper and lower sides of the test bench and installing the commutator. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0028] Figure 1 It is a structural schematic diagram of the special detection equipment of the present invention.

[0029] Figure 2 It is a top view of the special detection equipment of the present invention.

[0030] Figure 3 It is a cross-sectional view along the AA direction of the present invention.

[0031] Figure 4It is a side view of the ejector pin of the present invention.

[0032] Figure 5 It is a cross-sectional view along the BB direction of the present invention.

[0033] Figure 6 It is an enlarged view of location C of the present invention. DETAILED DESCRIPTION

[0034] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0035] Example 1 This embodiment provides a method for testing the pressure resistance performance of a pressure vessel, which uses dedicated testing equipment for testing.

[0036] like Figure 1-6 As shown, the special testing equipment includes a test bench 1, a transparent testing tube 2 and a pressure vessel clamp 5.

[0037] The test bench 1 is set horizontally.

[0038] The central axis of the transparent detection cylinder 2 is vertically arranged above the test bench 1. The transparent detection cylinder 2 includes a bottom support seat 21 and four side cylinders 22. The four side cylinders 22 are movably arranged around the bottom support seat 21 through a slider assembly 3, and are driven by a gear drive assembly 4 to synchronously move closer to or away from the bottom support seat 21. Each side cylinder 22 moves between a first position and a second position. When each side cylinder 22 synchronously moves to the first position, the transparent detection cylinder 2 is in an open state. When each side cylinder 22 synchronously moves to the second position, the transparent detection cylinder 2 is in a closed state. There are sealed connections between two adjacent side cylinders 22 and between the side cylinder 22 and the bottom support seat 21. The side cylinder 22 cooperates with the bottom support seat 21 to form a pressure vessel placement cavity. The top of the pressure vessel placement cavity has a first opening for the pressure vessel to enter.

[0039] The slider assembly 3 is arranged between the test bench 1 and the transparent detection tube 2. Each side cylinder 22 of the transparent detection tube 2 corresponds to two slider assemblies 3 arranged in parallel. The slider assembly 3 includes a slider 31, a guide rail 32 and a screw 33. The guide rail 32 is installed on the top surface of the test bench 1. The top of the slider 31 is connected to the bottom surface of the corresponding side cylinder 22. The bottom of the slider 31 is slidably installed on the guide rail 32. The screw 33 is rotatably arranged above the guide rail 32 through a mounting seat 34. The mounting seat 34 has two and is respectively installed on both sides of the guide rail 32. Both sides of the bolt are installed on the corresponding mounting seats 34 through bearings. A threaded hole matching the screw 33 is opened on the slider 31. The middle part of the screw 33 is threadedly connected in the threaded hole. The end of the screw 33 on one side close to the central axis of the transparent detection tube 2 extends out of the mounting seat 34 and is installed with a first gear 35.

[0040] The gear drive assembly 4 is arranged below the test bench 1. The gear drive assembly 4 includes a rotating motor 41 and a commutator 42. The commutator 42 is installed on the bottom surface of the test bench 1. The commutator 42 has a power input end and four power output ends corresponding to each side cylinder 22. The rotating motor 41 is installed below the commutator 42 through a motor fixing seat 44. The rotating end of the rotating motor 41 is connected to the power input end of the commutator 42. Each power output end of the commutator 42 is installed with a second gear 43. A through groove 11 is opened on the test bench 1 for each second gear 43 to extend out. The second gear 43 extends to the top of the test bench 1 through the through groove 11 and is meshed with the first gear 35 of the two slider assemblies 3 of the corresponding side cylinder 22. The first gears 35 of the two slider assemblies 3 of the side cylinder 22 are symmetrically meshed on both sides of the corresponding second gear 43.

[0041] A pressure vessel liquid outlet pipe positioning groove 211 is opened in the middle of the top surface of the bottom support seat 21, and three pressure vessel support blocks 212 are evenly arranged around the pressure vessel liquid outlet pipe positioning groove 211 on the top surface of the bottom support seat 21. The top surface of the pressure vessel support block 212 has an arc-shaped surface that matches the outer wall of the lower end of the pressure vessel.

[0042] The side cylinder 22 includes a bottom plate 221, a side plate 222, an intermediate plate 223 and a plurality of ejector pins 224. The side plate 222 is a closed-loop structure. The side plate 222 is arranged around the bottom plate 221 and forms a solution groove above the bottom plate 221. The intermediate plate 223 is arranged inside the side plate 222 and separates the solution groove into a phenolphthalein accommodating chamber b with a second opening on the top and a deformation color developing chamber c. The phenolphthalein accommodating chamber b is located on the inner side of the deformation color developing chamber c. A plurality of sleeves 225 corresponding to the ejector pins 224 are arranged in the phenolphthalein accommodating chamber b. The sleeves 225 are arranged in a matrix. Both ends of the sleeves 225 are connected to the side plates 222 and the intermediate plate 223. Three through holes 2231 for connecting the phenolphthalein accommodating chamber b and the deformation color developing chamber c are evenly opened around the sleeve 225 on the intermediate plate 223.

[0043] The ejector pin 224 includes a rod body 2241, one end of the rod body 2241 extends outwardly in the radial direction to form a disc 2242, and the end of the disc 2242 on one side close to the phenolphthalein accommodating chamber b extends outwardly in the axial direction to form a blocking block 2243. There are three blocking blocks 2243 and they correspond one to one with the through holes 2231. A second distance is left between the blocking blocks 2243 and the rod body 2241. The second distance is greater than or equal to the wall thickness of the sleeve 225, which is conducive to simplifying the processing process and avoiding interference of the sleeve 225 with the through hole 2231. The side of the blocking block 2243 away from the rod body 2241 is an inclined surface, which is inclined from the side close to the phenolphthalein accommodating chamber b to the direction away from the central axis of the rod body 2241. The side wall of the middle plate 223 close to the deformation color display chamber c is provided with a disc accommodating groove 2232 for the disc 2242 to enter. The through hole 2231 is provided on the bottom surface of the disc accommodating groove 2232. The shape of the through hole 2231 matches the blocking block 2243. The rod body 2241 is movably arranged in the sleeve 225 through the reset spring 2245 and is connected with the sleeve 2 25 is sealed and connected, a spring stopper 2244 is extended outwardly in the radial direction on the side wall of the rod body 2241, a stopper slot 2251 is opened on the inner wall of the sleeve 225 to accommodate the spring stopper 2244 and allow the spring stopper 2244 to move with the ejector 224, the spring stopper 2244 is arranged in the stopper slot 2251, the return spring 2245 is sleeved on the outside of the rod body 2241, one end of the return spring 2245 is connected to the spring stopper 2244, and the other end is connected to the side wall of the stopper slot 2251. The blocking blocks 2243 of the ejector 224 are sealed and pressed in the through hole 2231 under the pulling force of the return spring 2245, and the end of the ejector 224 away from the blocking block 2243 extends into the pressure vessel placement cavity.

[0044] There are two pressure vessel clamps 5, which are symmetrically arranged on both sides above the transparent detection tube 2. The two pressure vessel clamps 5 are driven by a linear drive 51 to move closer to or farther from each other. Two columns 52 corresponding to the pressure vessel clamps 5 are installed on the top surface of the test bench 1. The linear drive 51 is installed on the top of the column 52 on the side away from the transparent detection tube 2. The pressure vessel clamps 5 are arranged between the two columns 52. The telescopic end of the linear drive 51 passes through the column 52 and is connected to the corresponding pressure vessel clamps 5.

[0045] In this embodiment, the sealing connection between two adjacent side cylinders 22, between the side cylinder 22 and the bottom support seat 21, between the ejector pin 224 and the sleeve 225, and between each blocking block 2243 of the ejector pin 224 and the hole wall of the through hole 2231 are all achieved by installing a sealing strip, and the installation of the sealing strip belongs to conventional technology and will not be described here. In this embodiment, in order to facilitate the observation of color changes and record the color development position, a camera 6 is installed on each column.

[0046] The pressure resistance performance testing method of a pressure vessel using the above-mentioned special testing equipment in this embodiment includes the following steps: Step 1, reagent preparation: prepare methyl orange solution, phenolphthalein solution and alkaline solution in three reagent tanks respectively, sample the solutions after the preparation is completed, mix the methyl orange solution sample with the alkaline solution sample, and the phenolphthalein solution sample with the alkaline solution sample respectively, and observe whether the color changes; In this embodiment, the alkaline solution is a sodium bicarbonate solution, which has a weak alkalinity and low corrosiveness to the surface of the transparent detection tube 2 and the pressure container. It is also inexpensive and can reduce the detection cost.

[0047] Step 2, equipment preparation: operate the special testing equipment, make the transparent testing tube 2 and the pressure vessel clamping jaw 5 of the special testing equipment in the open state, check whether the ejector pin 224 on the special testing equipment is normal, push the inner end of the ejector pin 224 during the inspection, and observe whether the ejector pin 22 can move outward. If it moves, the ejector pin 224 is normal. After the inspection is completed, ensure that all ejector pins 224 are in the closed state.

[0048] Step 3, hoisting the pressure vessel: draw an axial positioning line on the outer wall of the pressure vessel in advance, and draw an axial positioning reference line on the transparent detection tube 2 of the special detection equipment, use the lifting equipment to hoist the pressure vessel in a normal state (that is, the central axis of the pressure vessel is vertical, and the lower end of the pressure vessel is at the bottom) into the transparent detection tube 2 of the special detection equipment, first make the outlet pipe at the bottom of the lower end of the pressure vessel enter the outlet pipe positioning groove 211 of the pressure vessel, rotate the pressure vessel, make the circumferential positioning line on the pressure vessel overlap with the axial positioning reference line on the transparent detection tube 2 to complete the positioning, and lower the pressure vessel to be supported by the pressure vessel. The support block 212 is supported, and the linear drive 51 is started to push the pressure vessel clamps closer to each other, and the top of the pressure vessel is supported and fixed to achieve the fixation of the pressure vessel; then the rotating motor 41 is started, and the commutator 42, the second gear 43, the first gear 35, the screw 33, and the slider 31 drive the side cylinders 22 to synchronously close the transparent detection cylinder 2, so that a crack color development cavity a is formed between the inner wall of the transparent detection cylinder 2 and the outer wall of the pressure vessel. At this time, a first distance equal to the maximum allowable deformation value of the pressure vessel is left between the inner end of the ejector pin 224 of the special detection equipment and the outer wall of the pressure vessel, and the lifting equipment is unhooked.

[0049] Step 4, pipeline connection: connect the pipeline between the methyl orange solution reagent tank and the pressure vessel, and the pipelines between the other two reagent tanks and the special detection equipment, and perform a sealing test on each pipeline, wherein the pipeline sealing test pressure between the methyl orange solution reagent tank and the pressure vessel is 1.2 to 1.5 times the maximum pressure value required for the pressure vessel test, and the pipelines between the other two reagent tanks and the special detection equipment are leak-free.

[0050] Step 5, reagent injection: inject methyl orange solution and phenolphthalein solution into the pressure vessel and phenolphthalein containing chamber b respectively, and inject alkaline solution into the crack color developing chamber a and the deformation color developing chamber c. When injecting the alkaline solution into the crack color developing chamber a and the deformation color developing chamber c, first inject the alkaline solution into the deformation color developing chamber c, and then inject the alkaline solution into the crack color developing chamber a. The liquid levels in the pressure vessel, the crack color developing chamber a, the phenolphthalein containing chamber b and the deformation color developing chamber c are all higher than the annular cylinder height of the pressure vessel, and the liquid level in the deformation color developing chamber c is lower than the liquid level in the phenolphthalein containing chamber b. After the injection is completed, observe the change of the liquid level in the crack color developing chamber a to ensure that the crack color developing chamber a does not leak.

[0051] Step 6, performance test: pressurize the pressure vessel to a safety pressure and maintain the pressure for 30 minutes. The safety pressure is within the range of 0.15~0.35MPa. Within this range, even if pressure leakage occurs, it will not pose a threat to the safety of equipment and personnel. Observe whether there is color change in the crack color display cavity a. If there is color change, record the color change position and stop the test. If there is no color change, intermittently pressurize the pressure vessel at a uniform speed according to the test requirements. After each pressurization to the required pressure value of a stage, maintain the pressure for 30 minutes until the pressure is increased to the maximum pressure value required by the test. After maintaining the pressure for 30 minutes, reduce the pressure to 80% of the maximum pressure value required by the test and maintain the pressure for 1~2 hours. During the experiment, continuously observe the color changes in the deformation color display cavity c and the crack color display cavity a. Once the color changes in the deformation color display cavity c or the crack color display cavity a, record the color change position and pressure value, stop the test and release the pressure.

[0052] Step 7, end of the test: after stopping the test, the pressure in the pressure vessel is released, the solutions in the pressure vessel, the crack color development chamber a, the phenolphthalein containing chamber b and the deformation color development chamber c are emptied, the special detection equipment is operated, the transparent detection tube 2 and the pressure vessel clamping jaw 5 of the special detection equipment are opened, and the pressure vessel is lifted away from the special detection equipment by using the lifting equipment; If the test is stopped due to the color change of the deformation color development cavity c, after the solution in the pressure vessel, the crack color development cavity a, the phenolphthalein containing cavity b and the deformation color development cavity c is emptied, the position of the opened ejector pin 224 is observed and recorded, and the position of the opened ejector pin 224 is rechecked against the color change position of the deformation color development cavity c recorded in step 6. The inspector then determines the crack or deformation position corresponding to the pressure vessel based on the color change position in each color development cavity, the circumferential positioning line on the pressure vessel and the axial positioning reference line on the transparent detection tube 2 as reference.

[0053] The detection method of this embodiment uses methyl orange and alkaline solution to develop yellow color, and phenolphthalein and alkaline solution to develop red color, so that the detection personnel can promptly determine whether the pressure vessel has cracks and deformation, accurately record the corresponding pressure, and identify the location of the cracks and deformation of the pressure vessel according to the location of the color change. In addition, the two different color changes enable the detection personnel to accurately distinguish between the two situations of cracks and deformation, thereby facilitating the detection personnel to take corresponding measures in time and stop the test in time, thereby improving the detection efficiency and detection safety.

[0054] Example 2 This embodiment uses the special testing equipment and testing method of embodiment 1 to test the pressure resistance performance of a No. 1 pressure vessel with an inner diameter of 200 mm. The testing requirements are as follows: The maximum allowable deformation value is 1% of the inner diameter, i.e. 2mm; The maximum pressure value required for detection is 1.5MPa; The pipeline tightness test pressure is 1.2 times the maximum pressure value required for the pressure vessel test, that is, 1.8MPa.

[0055] The five pressure stages are 0.3MPa, 0.6MPa, 0.9MPa, 1.2MPa and 1.5MPa respectively. In the last stage, the pressure is increased to 1.5MPa and maintained at this pressure for 30min, then reduced to 1.2MPa and maintained at this pressure for 2h.

[0056] After testing, it was found that there was no color change in the deformation color display cavity c and the crack color display cavity a in the transparent detection tube during the entire test process, and the No. 1 pressure vessel was qualified to withstand the pressure.

[0057] Example 3 This embodiment uses the special testing equipment and testing method of Example 1 to test the pressure resistance performance of a No. 2 pressure vessel with an inner diameter of 200 mm. The testing requirements are the same as those in Example 2.

[0058] During the inspection of pressure vessel No. 2, there was no color change in the crack color-developing cavity a in the transparent inspection tube. However, during the uniform pressurization process from the fourth stage to the fifth stage, when the pressure was increased to 1.4MPa, the deformation color-developing cavity c partially turned red, indicating that pressure vessel No. 2 deformed at the color-changing position, and the deformation exceeded the maximum allowable deformation value. The test was stopped, and the inspector marked the red position on the outer wall of the transparent inspection tube, emptied the solution in the pressure vessel, crack color-developing cavity a, phenolphthalein containing cavity b and deformation color-developing cavity c, observed and recorded the position of the opened ejector pin, and re-inspected the position of the opened ejector pin against the recorded color-changing position of the deformation color-developing cavity c. After re-inspection, it was found that the color-changing position covered the position of the opened ejector pin, indicating that the color-changing position corresponded well with the deformation of the pressure vessel. The final test result was that pressure vessel No. 2 failed the pressure-bearing test.

[0059] Example 4 In this embodiment, the special testing equipment of Example 1 is used to test the pressure resistance performance of a No. 3 pressure vessel with an inner diameter of 200 mm. The testing requirements are the same as those in Example 2.

[0060] In the detection method of this embodiment, fluorescein isothiocyanate is added to the methyl orange solution in step 1. In step 7, if the test is stopped due to the color change of the crack color development cavity a, after opening the transparent detection tube 2 and the pressure vessel clamp 5 of the special detection equipment, a purple light is used to illuminate the surface of the pressure vessel corresponding to the position where the color change occurs, and the crack position is marked on the wall of the pressure vessel according to the fluorescent indication position of the fluorescein. The rest of the detection process is the same as the detection method of Example 1.

[0061] During the inspection of pressure vessel No. 3, there was no color change in the deformation color-developing cavity c in the transparent inspection tube. However, during the uniform pressurization process from the first stage to the second stage, when the pressure was increased to 0.4MPa, the crack color-developing cavity a partially turned yellow, indicating that pressure vessel No. 3 had cracks at the color-changing position. The test was stopped, and the inspector marked the yellow-changing position on the outer wall of the transparent inspection tube. After draining the solution and opening the transparent inspection tube 2 and the pressure vessel clamp 5 of the special inspection equipment, the surface of pressure vessel No. 3 corresponding to the color-changing position was illuminated with a purple light, and it was found that there were obvious fluorescent fine lines formed by the accumulation of fluorescent pigment at the cracks, i.e. the crack positions. Pressure vessel No. 3 failed the pressure test.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for testing the pressure resistance of a pressure vessel, characterized in that: The following steps are involved: Step 1, reagent preparation: prepare methyl orange solution, phenolphthalein solution and alkaline solution in three reagent tanks respectively, sample the solutions after the preparation is completed, mix the methyl orange solution sample with the alkaline solution sample, and the phenolphthalein solution sample with the alkaline solution sample respectively, and observe whether the color changes; Step 2, equipment preparation: operate the special testing equipment, make the transparent testing cylinder and the pressure vessel clamp of the special testing equipment in the open state, check whether the ejector pins on the special testing equipment are normal, and ensure that all ejector pins are in the closed state; Step 3, hoisting the pressure vessel: use the lifting equipment to hoist the pressure vessel into the transparent detection tube of the special detection equipment for positioning support, operate the special detection equipment to close the transparent detection tube of the special detection equipment and the pressure vessel clamp, and unhook the lifting equipment; Step 4, pipeline connection: connect the pipeline between the methyl orange solution reagent tank and the pressure vessel, and the pipelines between the other two reagent tanks and the special testing equipment, and perform a sealing test on each pipeline; Step 5, reagent injection: a crack color development cavity is formed between the pressure vessel and the transparent detection tube of the special detection equipment, and the detection tube of the special detection equipment has a phenolphthalein containing cavity and a deformation color development cavity. Methyl orange solution and phenolphthalein solution are respectively injected into the pressure vessel and the phenolphthalein containing cavity, and alkaline solution is injected into the crack color development cavity and the deformation color development cavity. After the injection is completed, the liquid level change in the crack color development cavity is observed to ensure that the crack color development cavity does not leak; Step 6, performance test: pressurize the pressure vessel to a safe pressure and maintain the pressure for 30 minutes, observe whether there is any color change in the crack color-developing cavity, if there is any color change, record the location of the color change and stop the test, if there is no color change, intermittently pressurize the pressure vessel at a uniform speed according to the test requirements, maintain the pressure for 30 minutes after each pressure increase to the required pressure value of a stage, until the pressure is increased to the maximum pressure value required by the test, after maintaining the pressure for 30 minutes, reduce the pressure to 80% of the maximum pressure value required by the test, and maintain the pressure for 1-2 hours. During the experiment, continuously observe the color change in the deformation color-developing cavity and the crack color-developing cavity, once the color change occurs in the deformation color-developing cavity or the crack color-developing cavity, record the location of the color change and the pressure value, stop the test and release the pressure; Step 7, end of the test: After stopping the test, release the pressure in the pressure vessel, vent the solutions in the pressure vessel, crack color development chamber, phenolphthalein containing chamber and deformation color development chamber, operate the special detection equipment, open the transparent detection tube and pressure vessel clamp of the special detection equipment, and use the lifting equipment to lift the pressure vessel away from the special detection equipment.

2. The method for testing the pressure resistance performance of a pressure vessel according to claim 1, characterized in that: The alkaline solution is a sodium bicarbonate solution.

3. The method for testing the pressure resistance performance of a pressure vessel according to claim 2, characterized in that: In the step 1, fluorescein isothiocyanate is added to the methyl orange solution. In the step 7, if the test is stopped due to the color change of the crack color development chamber, after opening the transparent detection tube and the pressure vessel clamp of the special detection equipment, a purple light is used to illuminate the surface of the pressure vessel corresponding to the position where the color change occurs, and the crack position is marked on the wall of the pressure vessel according to the fluorescent indication position of the fluorescein.

4. The method for testing the pressure resistance performance of a pressure vessel according to claim 1, characterized in that: In step 3, when hoisting the pressure vessel, an axial positioning line is drawn on the outer wall of the pressure vessel in advance, and an axial positioning reference line is drawn on the transparent detection tube of the special detection equipment. When the pressure vessel is hoisted normally into the transparent detection tube of the special detection equipment by using the lifting equipment, the pressure vessel is rotated so that the circumferential positioning line on the pressure vessel overlaps with the axial positioning reference line on the transparent detection tube.

5. The method for testing the pressure resistance performance of a pressure vessel according to claim 1, characterized in that: In step 5, when injecting the alkaline solution into the crack color development cavity and the deformation color development cavity, the alkaline solution is first injected into the deformation color development cavity, and then the alkaline solution is injected into the crack color development cavity; The liquid level in the deformation color development chamber is lower than the liquid level in the phenolphthalein containing chamber.

6. The method for testing the pressure resistance performance of a pressure vessel according to claim 1, characterized in that: In step 7, if the test is stopped due to color change in the deformation color developing chamber, after venting the solutions in the pressure vessel, the crack color developing chamber, the phenolphthalein containing chamber and the deformation color developing chamber, the position of the opened ejector pin is observed and recorded, and the position of the opened ejector pin is rechecked against the color change position of the deformation color developing chamber recorded in step 6.

7. The method for testing the pressure resistance performance of a pressure vessel according to claim 1, characterized in that: The special testing equipment includes a test bench, a transparent testing tube and a pressure vessel clamp; The test bench is arranged horizontally; The central axis of the transparent detection cylinder is vertically arranged above the test bench. The transparent detection cylinder includes a bottom support seat and a plurality of side cylinders. The plurality of side cylinders are movably arranged around the bottom support seat through a slider assembly and are driven to synchronously move close to or away from the bottom support seat by a gear drive assembly. Each side cylinder moves between a first position and a second position. When each side cylinder synchronously moves to the first position, the transparent detection cylinder is in an open state. When each side cylinder synchronously moves to the second position, the transparent detection cylinder is in a closed state. Two adjacent side cylinders and between the side cylinder and the bottom support seat are sealed. The side cylinder cooperates with the bottom support seat to form a pressure vessel placement cavity. The top of the pressure vessel placement cavity has a first opening for the pressure vessel to enter. A pressure vessel outlet pipe positioning groove is provided in the middle of the top surface of the bottom support seat, and a plurality of pressure vessel support blocks are evenly arranged around the pressure vessel outlet pipe positioning groove on the top surface of the bottom support seat, and the top surface of the pressure vessel support block has an arc-shaped surface matching the outer wall of the lower end of the pressure vessel; The side cylinder comprises a bottom plate, a side plate, an intermediate plate and a plurality of ejector pins. The side plate is arranged around the bottom plate and forms a solution groove above the bottom plate. The intermediate plate is arranged inside the side plate and separates the solution groove into a phenolphthalein containing chamber with a second opening on the top and a deformation color developing chamber. The phenolphthalein containing chamber is located inside the deformation color developing chamber. A plurality of sleeves corresponding to the ejector pins are arranged in the phenolphthalein containing chamber. Both ends of the sleeve are connected to the side plate and the intermediate plate. A plurality of through holes connecting the phenolphthalein containing chamber and the deformation color developing chamber are evenly arranged around the sleeve on the intermediate plate. A plurality of blocking blocks corresponding to the through holes are arranged at the end of the ejector pin. The ejector pin is movably inserted into the sleeve by a reset spring and is sealed and connected to the sleeve. The blocking blocks of the ejector pins are sealed and pressed in the through holes under the pulling force of the reset spring. One end of the ejector pin away from the blocking block extends into the pressure vessel placement chamber. The pressure vessel clamping jaws are provided with two and are symmetrically arranged on both sides above the transparent detection tube. The two pressure vessel clamping jaws are driven by a linear drive to move closer to or farther from each other.

8. The method for testing the pressure resistance performance of a pressure vessel according to claim 7, characterized in that: The ejector pin comprises a rod body, one end of the rod body extends outwardly in a radial direction to form a disc, a side of the disc close to the phenolphthalein accommodating chamber extends outwardly in an axial direction to form a blocking block, a second distance is left between the blocking block and the rod body, a side of the blocking block away from the rod body is an inclined surface, the inclined surface is inclined from the side close to the phenolphthalein accommodating chamber to the direction away from the central axis of the rod body, a disc accommodating groove for the disc to enter is formed on the side wall of the middle plate close to the deformation color development chamber, a through hole is formed on the bottom surface of the disc accommodating groove, and the shape of the through hole matches the blocking block; A spring limit block extends outwardly in the radial direction on the side wall of the rod body, and a limit block accommodating groove for accommodating the spring limit block and allowing the spring limit block to move with the ejector pin is opened on the inner wall of the sleeve. The spring limit block is arranged in the limit block accommodating groove, and the return spring is sleeved on the outside of the rod body. One end of the return spring is connected to the spring limit block, and the other end is connected to the side wall of the limit block accommodating groove.

9. The method for testing the pressure resistance performance of a pressure vessel according to claim 7, characterized in that: In step 3, when the transparent detection tube of the special detection device is closed, a first distance is left between the inner end of the ejector pin of the special detection device and the outer side wall of the pressure vessel, and the first distance is the same as the maximum allowable deformation value of the pressure vessel.

10. The method for testing the pressure resistance performance of a pressure vessel according to claim 7, characterized in that: The slider assembly is arranged between the test bench and the transparent detection cylinder. Each side cylinder of the transparent detection cylinder corresponds to two slider assemblies arranged in parallel. The slider assembly includes a slider, a guide rail and a screw. The guide rail is installed on the top surface of the test bench. The top of the slider is connected to the bottom surface of the corresponding side cylinder. The bottom of the slider is slidably installed on the guide rail. The screw is rotatably arranged above the guide rail through a mounting seat. A threaded hole matching the screw is opened on the slider. The screw is threadedly connected in the threaded hole. A first gear is installed at the end of the screw. The gear drive assembly is arranged below the test bench, and the gear drive assembly includes a rotating motor and a commutator. The commutator is installed on the bottom surface of the test bench, and the commutator has a power input end and a plurality of power output ends corresponding to each side cylinder one by one. The rotating end of the rotating motor is connected to the power input end, and each power output end is equipped with a second gear. A through slot is opened on the test bench for each second gear to extend out. The second gear extends to the top of the test bench through the through slot and is meshed and connected with the first gears of the two slider assemblies of the corresponding side cylinder.

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